The present invention relates to a process for fabricating a heat sink, and more particularly to a process for fabricating a heat sink with high-density fins.
An integrated circuit chip is widely used in an electrical appliance such as a computer. When the electrical appliance operates, the chip generates energy in the form of heat. If the chip is unable to transfer enough heat to ambient air, the elevated operating temperature may result in damage of the chip or the breakdown of the whole appliance. In order to remove most heat generated from the chip, especially a CPU (central processing unit), a heat sink is usually provided and attached on the top surface of the chip. The heat sink is made of a highly thermal conductive material such as aluminum and copper and has a larger surface area than the attached chip for improving heat transfer. Since the surface area has a major influence on the overall heat transfer, the heat sink is generally constructed to have a flat base with a plurality of parallel fins or pin fins extending outwardly therefrom. Furthermore, in order to dissipate more heat, a heat sink with a greater number of fins, which is referred as a high-density fin heat sink, is developed.
The typical process for fabricating heat sinks includes an extrusion process, a gang sawing process and a bonding process. It is known that the thickness and number of fins produced by the extrusion process are restricted by the structural limitation and stress loading limitation of a die. If the number of fins increases, the die fingers become weaker and thus easily break off. Therefore, the extrusion process is not suitable for fabricating the high-density fin heat sink. The gang sawing process is performed by cutting off portions of a metal block to produce fins having predetermined thickness, number, depth and gap, which results in a great loss of material. In the bonding process, each fin is individually bonded into a base of a heat sink, which is time-consuming and labor intensive. In addition, the fins which are not well-bonded into the base are likely to fall and thus be detached from the base.
Therefore, the present invention provides an improved process for fabricating a heat sink with high-density fins for overcoming the problems described above.
It is an object of the present invention to provide a process for fabricating a heat sink with high-density fins, which is less costly and more timesaving than prior art.
It is another object of the present invention to provide a process for fabricating a heat sink with high-density fins, wherein the height, thickness and gap of the fins can be predetermined.
In accordance with an aspect of the present invention, there is provided a process for fabricating a heat sink with high-density parallel fins. The process includes steps of:
providing a metal block including a first base and a second base, the first base being rectangular-solid shaped, the second base being rhombus-shaped and disposed over the first base wherein the second base includes a first edge surface and a second edge surface inclined at a specific angle;
cutting the second base from a position on the top surface of the second base and parallel with the first edge surface until the first base is reached, thereby forming an inclined sheet;
adjusting the inclined sheet to be normal to the top surface of the first base, thereby forming a fin; and
repeating the cutting step and the adjusting step to produce the heat sink with high-density parallel fins.
Preferably, the first base and the second base are integrally formed.
Preferably, the specific angle is in the range from 20 to 80 degrees; and more preferably in the range from 30 to 60 degrees.
In accordance with another aspect of the present invention, there is provided a process for fabricating a heat sink with high-density pin fins. The process includes steps of:
(a) providing a metal base block including a first base and a second base, the first base being rectangular-solid shaped, the second base being rhombus-shaped and disposed over the first base wherein the second base includes a first edge surface and a second edge surface inclined at a first specific angle and a third edge surface and a fourth edge surface inclined at a second specific angle;
(b) cutting the second base from a first position on the top surface of the second base and parallel with the first edge surface until the first base is reached, thereby forming an inclined sheet;
(c) adjusting the inclined sheet to be normal to the top surface of the first base, thereby forming a first fin;
(d) repeating the step (b) and the step (c) to produce a plurality of the first fins;
(e) cutting the second base from a second position on the top surface of the second base and parallel with the third edge surface until the first base is reached, thereby forming a plurality of inclined pins in a row;
(f) adjusting the plurality of inclined pins to be normal to the top surface of the first base, thereby forming a plurality of pin fins in a row; and
(g) repeating the step (e) and the step (f) step to produce a heat sink with high-density pin fins.
Preferably, the first base and the second base are integrally formed.
Preferably, the first specific angle is in the range from 20 to 80 degrees; and more preferably in the range from 30 to 60 degrees.
Preferably, the second specific angle is in the range from 20 to 80 degrees; and more preferably in the range from 30 to 60 degrees.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: